Starter switch



May 22, 1956 F. A. KOMMER ETAL STARTER SWITCH Filed Aug. 18. 1952 FIG.|.

INVENTOR. FRED A. KOMMER ALBERT W. ZUB

FIG.3.

ATTORNEY United States Patent STARTER SWITCH Fred A. Kommer and Albert W. Zub, St. Louis, Mo., as-

signors to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application August 18, 1952, Serial No. 304,879

6 Claims. (Cl. ZOO-61.9)

This invention relates to starting systems for internal combustion engines and consists particularly in a novel, semi-automatic starter switch device with exceptional stability and adjustability.

A familiar self-starter system for automotive engines includes a solenoid having a winding which advances the starting pinion into meshing engagement with the fly-wheel gear and a second, lighter winding which, thereafter, independently holds such engagement during cranking. The solenoid, usually, is energized through a relay which, in turn, is closed or picked up by a manual starting switch. In certain cases, the starter switch is operated by or with the accelerator pedal, as in Coffey Reissue Patent No. 22,385, and if the starter pedal is not firmly held in the starting position by the operators foot, the circuit may be unstably or intermittently closed which causes arcing and abnormal heating of the relay points with resultant danger of damage thereto.

In a copending application, Serial No. 294,517, filed June 19, 1952, in the name of Fred A. Kommer, there is illustrated a throttle-operated starter switch device which incorporates either a snap-action or lost-motion connection to the switch bridging contact so that in the closed switch position, the actuator is capable of slight retraction and jiggling without opening the switch contacts. In the above device, however, the switch adjusting shims were located within the lost motion connection between the switch actuator and the bridging contact so that modification of the switch adjustment also affects the amount of lost motion between the actuator plunger and the switch bridging contact in an undesirable manner.

Accordingly, the main object of the present invention is to improve the switch device illustrated in the above copending application by wholly segregating the switch adjusting feature from the lost-motion connection between the switch bridging contact and its actuating plunger.

In the accompanying drawing which illustrates the invention Fig. l is a partial vertical transverse section, taken on two different planes, and illustrating the lower part of an automotive carburetor with the novel starter switch device mounted thereon, the switch being shown in the closed position.

Fig. 2 is an enlarged, horizontal transverse section taken on line 22 of Fig. 1.

Fig. 3 is a view similar to Fig. 2 but showing the switch closed.

Fig. 4 is a transverse section taken on line 4-4 of Fig. 3.

The carburetor shown in Fig. 1 has a downdraft mixture barrel 6 including venturi tubes 7 into which discharges a main fuel nozzle 8 extending upwardly at an angle from the usual float bowl 9 with which it is connected through a metering orifice element 10 controlled by a metering pin 11 controlled in any suitable way. Fuel for idling is supplied through a jet tube 12 and ports 13 connected therewith by means of passages, not shown. Fuel in the bowl is maintained at asubstantially constant level by means of a float 14 acting upon a needle valve 15. In the lower part of the mixture conduit is a butterfly throttle valve 16 mounted on a shaft 17.

Mounted on the outside of the mixture conduit adja cent the throttle valve is a starter switch casing 18 into which throttle shaft 17 projects, the portion of the shaft within the casing being recessed as at 19 to receive a ball 20 within a chamber 21, having a suction port 21a. Slidable within the casing is an actuator including separate plunger elements 22 and 23, member 22 having a generally cup-shaped recess 24 in its outer end telescopingly receiving member 23 which seats upon an annular shoulder 25 in recess 24. Normally received between plunger member 23 and shoulder 25 are switch adjusting shims 26, the number and thickness of which may be readily varied, upon disassembly of the plunger members, to modify and adjust the switch action. Inner plunger member 22 is of metal and has an arcuate recess 27 seating against ball 20. Outer plunger member 23 is of insulating material and, as best shown in Fig. 1, has an intermediate recess or slot 30 loosely receiving a modified, U-shaped spring clip 31 of resilient strip mate rial and constituting the movable bridging contact element of the switch. At the end of casing 18 is an insulating cap portion 32, secured to the casing by means of a bolt 33 and U clip 34, readily removable for inspection and adjustment of the switch. A pair of stationary switch contacts 35 are seated in insulating cap 32 and extend flush with the recessed inner wall thereof which forms an extension of the interior of casing 18.

A pin or plunger 36 is received longitudinally in cross bar 23 portion 37 at the outer extremity of insulating plunger member 23 and has an annular collar 38 which rests against the outer face of this bar and seats a coiled spring 39 compressed between the same and insulating casing cap part 32. Plungers 22, 23 and 36, which are connected in series relation, are held compressed by the action of the spring 39. The opposite end of pin or plunger 36 is slightly spaced from the inner portion of insulating plunger member 23, as at 38a, and bridging contact 31 extends between this pin and the inner end of plunger member 23 so that space 3811 establishes the lost motion connection between the plunger member and bridging contact 31. The leg portions 40 of insulating plunger member 23 snugly engage correspondingly shaped grooves in the inner wall of the recess in cap 32 (Fig. 4) to guide the plunger.

In operation, bridging contact 31 will be in the position shown in Figs. 1 and 2, when throttle valve 16 is closed. Upon opening of the throttle valve a predetermined degree, the actuator, including both plunger memhers, is bodily shifted leftwardly until bridging contact 31 engages the inner portion of insulating plunger member 23, as in Fig. 3. Thereafter, continued opening movement of the throttle moves the briding contact into engagement with stationary contacts 35 so as to close the switch. In this condition of the switch, the bridging contact is resiliently lodged between the stationary contacts so as to maintain its position until forcibly dislodged therefrom. At such time, the actuator is permitted slight retraction, that is rightward movement, within the limits established by space 38a of Figure 3, until pin 36 contacts the inner portion of the bridging contact. Thus, slight jiggling of the throttle pedal, when the switch is closed, does not tend to intermittently open the switch, with the possible damage to the starter circuit, as explained in the above mentioned copending application. Since adjusting shims 26 are independent of lost motion space 38a, modification of the number or thickness of these shims, in order to adjust the switch action, does not in any way afiect the lost motion connection between the bridging contact and the plunger member 23. Of course, when the engine starts to run under its own power, ball 20 will be picked up by suction transmitted through port 21a, as explained in the above mentioned Reissue Patent No. 22,385, so that during normal operation, the throttle may be operated freely in either direction without affecting the switch.

Certain modifications may be made in the structure illustrated without departing from the spirit of the invention, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

We claim:

1. A starting switch device for internal combustion engines comprising spaced, stationary switch contacts, a bridging contact therefor, and an actuator for said bridging contact comprising separate, aligned plunger members having spaced apart portions loosely receiving said bridging contact for shifting the same to and from switch closing position while permitting slight retraction and jiggling of said actuator, when in any switch closing position, without affecting said bridging contact, and switch adjusting means on said actuator operable independent of the spaced relation between said plunger members.

2. A starting switch device for internal combustion engines comprising spaced, stationary switch contacts, a bridging contact therefor, and an actuator for said bridging contact comprising separate, aligned plunger members loosely receiving said bridging contact for shifting the same to and from switch closing position while permitting slight retraction and jiggling of said actuator, when in any switch closing position, without affecting said bridging contact, and switch adjusting means between said plungers for modifying the switch action relationship of said actuator and bridging contact without affecting the spaced relation between said plunger members and said bridging contact.

3. A starting switch device for internal combustion engines comprising a switch chamber, spaced, stationary contacts in the wall thereof, a bridging contact, and a switch actuator movable in said chamber, said actuator comprising separable, aligned plunger members, there being adjustment means between said plunger members for modifying the switch closing relationship of said bridging contact and said actuator, and one of said plunger members having a recess loosely receiving said bridging contact and forming a lost motion, operative connection between said plungers independent of said adjustment, whereby the actuator, when in any switch closing position, is capable of at least slight retraction and jiggling without opening the switch points.

4. A starter switch device for association with an internal combustion engine carburetor having a throttle and a switch operating element movable therewith, comprising a switch casing, spaced stationary switch contacts in said casing, a bridging contact movable in said casing to and from a switch closing position resiliently lodged against said stationary contacts, and an actuator shiftable as a unit for transferring motion from said switch operating element to said bridging contact, said actuator comprising separate plunger members with switch adjusting shims therebetween, one of said plunger members extending to a point adjacent said switch operating element and another plunger member having a recess loosely receiving said bridging contact and forming a lost-motion, operative connection between said plungers whereby said actuator, in any switch closing position, is capable of at least slight retraction and jiggling without opening the switch.

5. A carburetor mounted starter switch for internal combustion engines comprising a switch casing adjacent the carburetor throttle, normally spaced stationary and movable contacts therein, and an actuator for transferring motion from the carburetor throttle to said movable contact, said actuator comprising aligned, separable plunger members longitudinally slidable in said casing, one of said plunger members having a recess loosely receiving said movable contact and forming a lost-motion operative connection between said plunger members whereby said actuator, when in its switch closing position, is capable of slight retraction and jiggling without atfecting said movable contact, there being adjustment shims between said plunger members for adjusting the switch action without affecting said lost-motion connection.

6. In combination with an internal combustion carburetor having a throttle and a part movable therewith, a switch casing adjacent said throttle, spaced stationary contacts in said casing, a spring strip bridging contact, an actuator for transferring motion from said throttle part to said bridging contact and comprising readily separable plunger members longitudinally slidable in said casing, one of said members extending adjacent said mentioned part for engagement thereby, upon opening of the throttle, to close the switch and another plunger member being formed of insulating material and having an element fitting with said first plunger member and an intermediate slot loosely receiving said bridging contact and forming a lost-motion connection with a third plunger member, said bridging contact in its closed position, being resiliently lodged between said stationary contacts, and said second plunger member, when the switch is closed, being capable of slight retraction and jiggling without affecting said bridging contact, there being adjustment shims between said plunger members for modifying the switch action without affecting said lost motion connection, and a spring stressed between said third plunger member and said casing for urging said actuator toward said throttle part and in the direction to open the switch.

References Cited in the file of this patent UNITED STATES PATENTS 1,862,006 Collins June 7, 1932 2,123,133 Callsen July 5, 1938 2,174,313 Cofiey Sept. 26, 1939 2,234,015 Winkler et al Mar. 4, 1941 2,249,221 Moseley et a1 July 15, 1941 

